Method for the identification of a receptor

A method for the identification and characterization of a receptor in target tissue for which a selected vector has affinity, wherein a transfected cell line expressing the receptor is added to a suspension of encapsulated microbubbles to which the selected vector is coupled and allowing the microbubbles and cells coupled thereto to float to the surface of the suspension. Upon isolating the microbubble-bound cells at the surface, these may be cultured to study the receptor, or cells may be lysed, amplifying the receptor-encoding cDNA and sequencing the cDNA.